As a student in this field, you will often be asked these questions. Why does one study this subject? What type of work does a “coder” do? Basically, medical coding consists of translating diagnoses and procedures into numbers for the purpose of statistically capturing data. This process is done for us every day in all aspects of daily life. If you buy a banana at the grocery store, the cash register captures that banana as a number, which, in turn, provides data on the number of bananas sold in that store or by that grocery chain; it also yields data of importance to the store on replenishing their inventory, details regarding what time of year the greatest number of bananas are sold, and so forth.

Translation of a disease and/or a procedure into an ICD-10 code is not as simple as it may seem. This process requires a thorough knowledge of anatomy and physiology, disease processes, medical terminology, laboratory values, pharmacology, surgical procedures, and last but not least, a myriad of coding rules and guidelines. Diseases and procedures are translated into a coding system known as the International Classification of Diseases, 10th Revision, Clinical Modification ICD-10-CM and ICD-10-PCS. This classification system has been used worldwide and has been clinically modified for the United States.

Coded data are used for many purposes. Prior to the advent of diagnosis-related groups (DRGs), which are used by Medicare and other payers as the basis for hospital reimbursement (payment), coding was used for research and planning. A healthcare provider or facility could use this data to find out how many cases of appendicitis were treated in a year. This information could be used by a healthcare facility in decisions about the possible purchase of more equipment, the addition of an operating room, the hiring of additional staff, or by the provider to gain additional skills. Since the implementation of DRGs—now known as MS-DRGs—coded data are also used for reimbursement purposes, and they are increasingly used for risk management and quality improvement, as well as in nursing clinical pathways. Coded data were important from the start, but use of this data for reimbursement has elevated the importance of accurate coding to new heights.

Capture of health data through ICD-10 codes that are used worldwide has proved useful for the study of patterns of disease, disease epidemics, causes of mortality, and treatment modalities. Without the use of a classification system, comparison of data would be impossible.

Nomenclature and Classification

A nomenclature and a classification of diseases are required for development of a coding system. A nomenclature is a system of names that are used as preferred terminology, in this case, for diseases and procedures. Often, diseases in different areas of the country or in different countries are identified by dissimilar terminology, which makes the capture of comparative statistical data next to impossible. For example, another name for “amyotrophic lateral sclerosis” is “Lou Gehrig’s disease,” which is also known as a “motor neuron disease.” Nomenclatures of disease were first developed in the United States around 1928. The Systematized Nomenclature of Medicine (SNOMED), published by the College of American Pathologists, is the most up-to-date system in current use.

Classification systems group together similar items for easy storage and retrieval. Within a classification system, items are arranged into groups according to specific criteria. The history of classification systems goes back as far as Hippocrates. During the 17th century, London Bills of Mortality represented the first attempts of scientists to gather statistical data on disease. The ICD-10-CM classification system is a closed system that comprises diseases, injuries, surgeries, and procedures. In a closed classification system a disease, condition, or procedure can be classified in only one place.

History of Coding

ICD-9-CM is the coding classification system that is currently in use in the United States. This classification system dates back to Bertillon’s Classification of Causes of Death, which was developed in 1893. This system was adopted by the United States in 1898 under the recommendation of the American Public Health Association. System revisions were scheduled to take place every 10 years, and the classification was maintained by the World Health Organization (WHO). Revisions became known as the International Classification of Causes of Death. Over the years, this system has been changed to allow its use not only in mortality (death) reporting but in morbidity (disease condition) reporting as well. Since its inception, this classification has been revised 10 times. The Clinical Modification (CM) was developed in 1977 by the United States to more accurately capture morbidity data for study within the United States, as well as information on operative and diagnostic procedures that were not included in the original publication of ICD.

Currently, many countries are using ICD-10, which was published in 1993 by the WHO. ICD-10-CM has been clinically modified for use in the United States with proposed implementation set for October 1, 2014. ICD-10-CM will replace the 30-year-old ICD-9-CM. The final rule for adoption of ICD-10-CM and ICD-10-PCS was released in January of 2009.

Work on ICD-10 was begun in 1983. The tabular volume was published in 1992, and the instructional volume followed in 1993; the Alphabetic Index was published in 1994. In 1994, the United States began the process of determining whether a clinical modification (CM) would be necessary. A draft version was made available in 2002, updated in July 2007, and updated again in 2009 and will continue to be updated yearly until it is final. The latest version can be found at the National Center for Health Statistics website.

Clinical modifications made to ICD-10 allow a higher level of specificity. Since 1999, ICD-10 has been used in the United States for the reporting of mortality data. A total of 90 countries, including Canada and Australia, are currently using ICD-10.

ICD-9-CM may be updated biannually in April and October. Updates contain additional codes, revised codes, and codes that are deleted. These updates are published in the Federal Register (the official daily publication for rules, proposed rules, and notices of U.S. federal agencies and organizations) as a proposed rule and then as a final rule. They are available at the Centers for Medicare and Medicaid Services (CMS) website (www.cms.gov). It is of the utmost importance that code books and coding software (encoder) be updated to ensure that coding is accurate and to facilitate accurate reimbursement. The ICD-9-CM Coordination and Maintenance Committee meets twice a year and is used as a forum for proposals to update ICD-9-CM. Upon full implementation of ICD-10-CM/PCS this will become the ICD-10 Coordination and Maintenance Committee. This committee serves in an advisory capacity. Two federal agencies are responsible for maintenance of ICD-9-CM. The classification of diagnoses is the responsibility of the NCHS (National Center for Health Statistics), and the classification of procedures is the responsibility of CMS (Centers for Medicare and Medicaid Services). The Coordination and Maintenance Committee meetings are open to the public and comments are encouraged. All comments and recommendations are evaluated before a final decision on new codes is issued.

The development and maintenance of the guidelines of ICD-10-CM is the responsibility of the National Center for Health Statistics (NCHS), CMS, the American Hospital Association (AHA), and the American Health Information Management Association (AHIMA), which are also known as the Cooperating Parties. Many publications provide coding advice and information, but only one publication is official. This publication, AHA Coding Clinic for ICD-10-CM (referred to as Coding Clinic), which is published quarterly by the AHA, provides coding advice and guidelines that have been approved by the Cooperating Parties and must be followed by coders.

Preparation for Transition to ICD-10-CM

The steps necessary for transition to ICD-10-CM and ICD-10-PCS involve many different areas within the healthcare system, including information systems (IS), billing, healthcare providers, utilization review (UR), researchers, compliance, and accounting, to name a few. Most articles written on the subject recommend a team approach across the facility. Existing coding staff will need to be trained on both ICD-10-CM and ICD-10-PCS.

Reports suggest (Practice Brief Destination 10: Healthcare Organization Preparation for ICD-10-CM and ICD-10-PCS)1 that the knowledge base of coders must be broadened so they have detailed knowledge of anatomy and medical terminology, enhanced comprehension of operative reports, and a greater understanding of ICD-10-PCS definitions. It may be necessary to assess the skills of coders before selecting the type of training needed. It has been suggested that training should not take place too early, and probably around 3 months before implementation would be preferable. Aside from more intensive training in anatomy and physiology (A&P) and terminology, the following education on ICD-10-CM is recommended by AHIMA: